Devices for plumbing, or determining and forming a vertical line, have been used in the building and other trades since the earliest of times. Traditionally, these devices have basically consisted of nothing more than a weight suspended from a string or line, with the vertical line determined by gravity. More recently, various relatively complex plumbing and leveling devices have been developed, many of which rely upon the extremely narrow beam of a laser. However, these devices are generally quite costly, use bearings which develop at least some amount of friction which reduces their accuracy, require a relatively large amount of electrical power for operation, are prone to error due to numerous critically adjusted or set components which may be knocked or jarred out of alignment, and/or require a relatively skilled operator in order to produce accurate readings and to ensure proper handling of the apparatus in order to preclude damage thereto.
Accordingly, it has been recognized that simpler, less costly plumb bobs incorporating light means therein, may be valuable in such work. However, such lighted plumb bobs developed to this point rely upon an incandescent light source, which produces incoherent light which tends to spread even when focused through one or more lenses. As a result, such plumb bobs must be used conventionally close to the target and using a relatively long plumb line, in the manner of standard plumb bobs of long use. The only advantage of such lighted plumb bobs is their ability to be used in conditions of low light. However, the disadvantages of a relatively long plumb line, and the time required for oscillations to dampen, still remain.
The need arises for a plumb bob incorporating a relatively simple and low cost laser therein, which plumb bob may be suspended on a relatively short line at some distance from the target. The relatively short line provides relatively rapid damping of oscillations, and further provides for ease of protection from wind and other factors which might cause a conventional plumb line to oscillate. The extremely narrow laser beam provides great accuracy in determining the precise point vertically below the laser plumb bob, and is not affected by wind, diffusion of the light beam, or other factors. A further need exists for various devices or apparatus providing for the rapid deployment of a plumb bob and measurement of a vertical thereby, by a single person, thus freeing others to perform other tasks and reducing the labor costs involved in such plumbing operations.